Bioluminescence imaging is a simple and sensitive method to visualize disease progression and response to therapeutics in live mice. Routinely applied in many mouse disease models, bioluminescence is rarely used for imaging inflammatory processes of the airways and lungs in vivo. The fundamental factors limiting the application of BLI for lung and airway imaging are the relatively poor ability of the natural firefy luciferase substrate D-luciferin to access the lung and airways, strong signal attenuation due to absorption and scattering of visible-wavelength photons originating from deep tissues, and the lack of suitable lung or airway-specific luciferase reporters. We hypothesize that these problems can be overcome by synthetic luciferins that exhibit improved pharmacological access to lung and airway tissues and emit light at tissue- penetrating near-infrared wavelengths (Aim 1), and through the use of luciferase reporters whose expression is restricted to the airways (Aim 2). These luciferins and luciferase reporters will enable us to study the real-time regulation of gene expression in live mouse models of infections and allergic asthma, greatly improving our ability to continually monitor disease progression in the lung and response to therapeutics.